I've been using Photoshop for a while now and I've never found an error like this.
I needed to use the selection tool to cut out a part of an image and then paste it on a layer on top. However, whenever I do this there is a very obvious transparent line where I made the selection remaining.
The image is an example, made a circular selection around stomach I used the lasso tool, Ctrl-x then Ctrl-Shift-V to paste in place and then this is how it ends up.
I don't know what to do. Sorry if I posted this question in the wrong place, I'm new to Stack Exchange.
Thank you very much!